Expression of random analytical error as a precentage of the range of clinical interest.

I propose that random method error be expressed as a percentage of the range(s) of clinical interest (upper range limit minus lower range limit), in addition to its usual forms of presentation. The interpretation of this percent random error is simple because a given percentage error implies the same reliability, regardless of test or range of clinical interest. Two different upper limits for percent random analytical error are suggested, based on the medical application of the test and the statistical properties of various amounts of error. When the purpose of the test is to distinguish an upper medically defined limit from a lower medically defined limit, a maximum random error equivalent to 60% of the difference between the limits is proposed. If the purpose of the test is to monitor values in the neighborhood of a normal range or therapeutic range, an upper limit for random error equal to 20% of the difference between the limits of the range is suggested.

Variations of some plasma components after closed fractures.

1) Variations in the serum concentrations of total proteins and the electrophoretic fractions, glycoprotein, mucoprotein, fibrinogen, erythrocyte sedimentation rate, calcium, phosphorus, alkaline, and acid phosphatases were analyzed until the 30th day following uncomplicated fracture of shafts of long bones of the limbs in 25 cases. 2) A significant fall of albumin with concomitant rise of alpha 1, alpha 2, and beta globulins were noted until 30th day. 3) Mucoprotein, glycoprotein, and fibrinogen showed parallel elevations with that of alpha and beta globulins. 4) The peak values of alpha 1 and alpha 2 globulins, mucoprotein, and fibrinogen were registered on the 10th day after trauma. Albumin showed maximum fall on the 10th day in all these cases. 5) Glycoprotein showed a peak value on the 5th day. 6) Total protein and gamma globulin remained almost unchanged throughout the studies. 7) Beta globulin showed higher values and paralleled more closely the fibrinogen and erythrocyte sedementation rates. 8) The elevations of beta globulin, fibrinogen, and erythrocyte sedimentation rate were higher, and persisted beyond 30 days in lower-limb fractures as compared to upper-limb fractures. 9) Serum calcium, phosphorus, alkaline phosphatase, and acid phosphatase were not significantly different following fractures and therefore did not reflect much physiologic variation. 10) The most significant changes in the levels of plasma fractions studied were conspicuous on the 10th day and lasted for about 1 month.